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Roger Pielke Jr.: What the media won’t tell you about … Wildfires – Even the UN ‘IPCC has not detected or attributed fire occurrence or area burned to human-caused climate change’

What the media won’t tell you about … Wildfires

What the IPCC really says, trend data and the complexities of adaptation


Excerpt: Wildfire, common to many healthy ecosystems, is a particularly challenging problem for society because of its impacts on property and health. It is also challenging because people like to locate themselves in fire-prone places and do things that ignite fires. We have learned through hard experience that complete suppression of wildfire is not the best policy — despite what Smokey Bear says — as it can actually lead to even greater and more harmful wildfire events. These dynamics together make wildfire a challenging issue for policy.

This week, wildfire smoke from fires in Canada have drifted south along the eastern seaboard of the United States, affecting New York City and Washington, DC, and correspondingly capturing a lot of media attention. The event should offer a teachable moment on the complexities of climate and the challenges of adapting to a volatile world.

With this post I discuss some of the aspects of wildfires that I see as missing in the public discussion. I start with what the Intergovernmental panel on Climate Change (IPCC) says about wildfire, discuss readily available data on wildfire trends and conclude with the complexities of policy in the face of interconnected human-environment dynamics.

The IPCC has not detected or attributed fire occurrence or area burned to human-caused climate change

The IPCC is of course not infallible, but it is essential and always a good first place to start when discussing what is known about extreme events and their impacts. Many people are surprised when they learn that the IPCC does not evaluate trends in or causes of wildfires.

Instead, the IPCC focuses on “fire weather” which it defines as (emphasis in original):

“Weather conditions conducive to triggering and sustaining wildfires, usually based on a set of indicators and combinations of indicators including temperature, soil moisture, humidity and wind. Fire weather does not include the presence or absence of fuel load. Note: distinct from wildfire occurrence and area burned.”

Globally, emissions from wildfires has decreased globally over recent decades, as well as in many regions


The figure above shows that wildfire emissions have declined globally since 2003, based on data from the EU. That doesn’t mean that wildfires have decreased everywhere. For instance, wildfires have increased over recent decades in the Western United States, France and Russia. It does mean that claims that wildfire has increased globally in recent decades do not have empirical support, at least by this important and widely accepted metric.

Canada — the focus of extensive fire activity this week polluting the air in the eastern U.S. and elsewhere — has not seen an increase in fire activity in recent decades, as you can see in the figure below, showing official data.

Forest fires in Canada. Source: NFDP

In Quebec specifically, there is also no indication of a long-term increase in fire activity, as you can see below. In fact, recent years have been unusually quiet.

Forest fires in Quebec. Source: NFDP

Looking at data from the NFDP, we can see that the majority of fires in Quebec and the area that they burn over the past decade are caused by humans, with the balance caused by lightning, as shown in the figure below.

Over the much longer term, going back to 1700, research indicates that recent “burn rates” across Canada in recent decades have been much lower than in centuries past, as you can see in the figure below.